OF THE CELLULAR TISSUE. 117 



disposed, according to the form of the latter. The skin, the 

 mucous and serous membranes, the blood vessels, lympha- 

 tics and excretory canals which have only one surface free, 

 are connected with the cellular tissue on one side only, the 

 solid organs on the contrary, such as the muscles, are entirely 

 surrounded by it. Under the skin the cellular tissue forms a 

 layer generally extended, if we except the places where the 

 muscles and aponeuroses are inserted. This sub-cutaneous 

 tissue is more or less dense, according to the region it occu- 

 pies; it is the most so throughout the whole extent of the 

 median line, at the neck excepted, where this line is but 

 slightly defined. Bordeu has exaggerated this disposition in say- 

 ing that it divides the body into two halves: it is very evident, 

 that at a certain depth no traces of it are to be seen. In those 

 places where there is great motion, the cellular tissue is 

 more lax, as in the eye-lids, prepuce, scrotum, lips and vulva. 

 On the contrary, where the skin does not slide, as in the 

 palm of the hand, the sole of the foot, front of the sternum, 

 back, &c. it is tighter. The mucous membranes have their 

 adhering surfaces covered by a very dense cellular tissue, 

 usually styled the nervous membrane. That which covers 

 the adhering surfaces of the serous membranes is generally 

 flaky. That which is found round the canals, forms particu- 

 lar sheaths for them, particularly important to the arteries, but 

 it is also found about the veins, lymphatic trunks and excre- 

 tory ducts. This tissue forms a layer round the muscles, called 

 their common membrane. 



141. That portion of the cellular tissue which penetrates 

 into the organs, which accompanies and envelopes all their 

 parts textus cellularis stipatusi& differently disposed in 

 the different organs. In the muscles it forms an envelope for 

 each fasciculus, and smaller ones for the secondary fasciculi and 

 for the fibres of which these latter are composed: thus the cel- 

 lular tissue of a muscle exhibits a series of canals, sheathed suc- 

 cessively within each other, and connected in the same way that 

 the envelopes belonging to the different organs continue with 

 the general envelope of the body. The lobes of the glands, their 

 lobules, and the grains which compose these latter, are sur- 



